But they still hope to get their full-power license by then and produce electricity a month into the new year.

Plant officials reassessed their timetable after a Nuclear Regulatory Commission licensing board, in a report dated Thursday and released Friday, said it won’t be able to rule before Nov. 30 on evacuation plans for Seabrook.

The commission had pressed the Atomic Safety and Licensing Board for a ruling by Sept. 30.

Even though the board said in May it probably would not meet that target, on Friday a recorded telephone information line at Seabrook still said commercial operation was expected ″later this year.″

After the board rules, the commission would decide whether to give Seabrook the commercial license it hoped to have 10 years ago. Seabrook spokesman Ron Sher estimated Friday the commission would take a month to decide.

Seabrook foes vow to challenge any license in federal court. There has been one precedent for staying a full-power license, a four-month delay for the Diablo Canyon plant in California, though that reactor eventually was allowed to run commercially.

Once Seabrook gets final approval, Sher estimated it would take about one month to get the reactor to 10 percent power and start providing electricity to the region. He said it would take several months to reach 100 percent power.

The licensing board is deciding the adequacy of Seabrook’s evacuation plans for six Massachusetts communities within 10 miles of the plant that refuse to cooperate.

It also is to give a final grade on a June 1988 federal exercise of those plans and evacuation plans that New Hampshire developed for its 17 communities in the 10-mile zone.

Hearings on those issues concluded last week after 57 days.

Chairman Ivan Smith said the Nov. 30 target disregards Massachusetts Attorney General James Shannon’s plans to call for hearings on a reactor shutdown last month during low-power testing. Seabrook officials admit they wrongly delayed the shutdown, and the NRC took the unusual step of suspending the low-power tests.

Steve Jonas, an assistant Massachusetts attorney general, said he was pleased by Smith’s report.

″We think it also confirms what we’ve been saying for some time, which is these matters are more complex than (Seabrook) seems to recognize. They’re not going to get the license as quickly as they think,″ Jonas said. He said the plant’s past projections have proved ″whoppingly wrong.″